doi:10.1038/nindia.2012.148 Published online 15 October 2012
Soul is a name given by the spiritually-inclined to the life giving substance. The word itself does not describe its composition. Given that spirituality has traditionally probed this question in great detail, can science provide a parallel?
When a key component is knocked out from a system, some correlation is usually noticed. For example, knocking out a gene to know its function is a standard practice in molecular biology. Extending this logic to spirituality: the absence soul is noticed when a person dies.
Interestingly, immediately after death, genes, RNA molecules, proteins, pathways and networks are still in fully operational mode but the person is 'lifeless'. Common spiritual belief is that the missing substance that keeps people alive is the 'soul' or spirit.
At the highest level, living beings exhibit features in the form of mood variations. Physiologically these variations can be mapped in cell and molecule interactions. The interactions are determined by the chemistry that exists between molecules. Chemistry is further determined by the physical atomic structure. An atom is held in shape by a strong physical force that exists among sub-atomic particles. Though protons and neutrons were considered fundamental particles, they are in turn made of quarks. Quarks are held together by a strong force called 'colour charge' mediated by particles called gluons.
Though the current model of atom describes several fundamental forces and particles, it is unable to explain how living beings are constitutionally different from the non-living. From ancient times, a force has been described in spiritual texts as the 'life giving substance', spirit or soul. A scientific parallel to that has not yet been described.
The electromagnetic spectrum describes all possible frequencies of electromagnetic radiation ranging from long wavelength used for radio communication to short wavelength gamma radiations. In theory, long wavelengths can extend upto the size of the universe itself, while the short wavelength can be as short as the Planck length.
If the life giving force exists, can we we find a 'soul spectral signal' in the electromagnetic spectrum? If yes, how would it possibly look like? Would it show up in the middle of the spectrum, towards the gamma ray end (shortest wavelength) or towards the radio wave length (longest wavelength) end? There is no scientific evidence to support or refute this theory.
Periodic table in chemistry is a benchmark to understand and predict the property of basic elements that make the universe. If we draw a parallel with the soul again, for this hitherto non-quantifiable entity to form its own periodic table, we have to assume that it has a heterogenous composition and is a compound, not a pure element.
Though the possibility of a homogenous or pure composition sounds more attractive, we do not have any evidence to prove that. If we go with the homogenous 'color charge' force as the most subtle one detected so far, this by itself does not explain the difference between living and non-living.
Its worth quoting an interesting example from Kashmiri Shaivism where one comes across a potential lab manual to 'construct a living being'. The inventory prescribed there comprises of 36 elements, with inert energy (Shiva) and dynamic energy (Shakti) as the foundation elements. Unfortunately, it is unclear what inert or dynamic energy itself is made of. How is this energy different in composition from the existing known forces of the universe?
In science, the zero-point energy paradigm based on the stochastic electrodynamics foundation points to the lowest possible energy level that a quantum mechanical physical system can exhibit. In addition, Heisenberg's uncertainty principle requires every physical system to have a zero-point energy greater than the minimum of its classical potential well, even at absolute zero.
Given that zero point energy has several unique features — it imparts stability to the system, is presumed to pervade across the universe and maintains stability of atomic orbitals in the universe — it is tempting to look for any imprints of the existence of soul in the zero point energy space.
Dark energy is the mysterious energy-fluid that causes unexplained cosmic expansion. Though dark matter and dark energy make bulk of space that we call nothingness, its particles interact very weakly with ordinary matter, making their detection via interactions with ordinary matter extremely difficult.
Current scientific evidence indicates that the universe is composed of 92-93% dark energy and dark matter1. Logically this data suggests that the probability of finding soul energy imprints in the space of nothingness is more than 90%. This is a huge number and statistically very attractive. If it is true that soul is a "special extract of nothingness" then the question would be: does soul exist?
The search for physical correlates of soul or spirit is a grand challenge in science.
If soul is composed of nothingness, an attempt to find its signature on the electromagnetic spectrum would be very difficult as dark energy does not generate a single frequency peak. One gets a frequency signature proportional to the volume of space involved. Moreover, the result would be contextual and dependent upon the emergent behaviour of unknown fundamental particles.
Given that even space and time are surmised to emerge only after the Big Bang, it would be interesting to look for clues on whether the soul described in spiritual texts is surmised to have taken shape before that or was constructed later de-novo?
Though science has made enormous progress in the field of subatomic physics, it is clear that more fundamental forces are waiting to be discovered to explain the existence and dynamics of the life giving substance.
This is the fifth and final article in a series entitled 'Science and spirituality'.